Continuing improvements in circuit manufacturing technologies in developing smaller sized components for achieving higher operational frequencies (smaller wavelengths) has been accompanied by a need to reduce the dimensions of both signal processing and interface circuitry support hardware and their associated radio frequency antenna structures. In such reduced size, high frequency communication systems, helically wound antennas, such as those supported by low loss foam cores, are particularly attractive, as their radiation characteristics and relatively narrow physical configurations readily lend themselves to implementing physically compact phased array architectures that provide for electronically controlled shaping and pointing of an antenna's directivity pattern.
However, as operational frequencies have reached into the multidigit GHz range, achieving dimensional tolerances in large numbers of like components has become a major challenge to system designers and manufacturers. For example, in a relatively large number element phased array antenna operating at frequency in a range of 15-35 GHz, and containing several hundred to a thousand or more antenna elements, each antenna element may have on the order of twenty turns helically wound within a length of only several inches and a diameter of less than a quarter of an inch.
While conventional fabrication techniques, such as those which employ crossed-slat templates, diagrammatically illustrated in FIG. 1 at 11 and 12 to form a winding 14, may be sufficient to form helical windings for relatively large sized applications (since relatively small variations in dimensions or shape may not significantly degrade the electrical characteristics of the overall antenna), they are inadequate for very small sized elements (multi-GHz applications), where minute parametric variations are reflected as substantial percentage of the dimensions of each element. As a consequence, unless each element is effectively identically configured to conform with a given specification, there is no assurance that the antenna will perform as intended. This lack of predictability is essentially fatal to the successful manufacture and deployment of a high numbered multi-element antenna structure, especially one that may have up to a thousand elements.